title: Cross-examination of liquid-liquid extraction (LLE) and solid-phase microextraction (SPME) methods for impurity profiling of methamphetamine.
abstract: Impurities in 48 methamphetamine (MA) samples were analyzed by liquid-liquid extraction (LLE) and headspace solid-phase microextraction (HS-SPME) methods. MPS-2 autosampler was used to improve reproducibility of SPME method, and nonadecane (C(19)) diluted with potassium bromide (KBr) powder was used as an internal standard for standardizing retention time. Impurities identified by SPME method showed different patterns compared with LLE method. Non-volatile impurities like methamphetamine dimer were not identified by SPME method, but some volatile impurities like diphenylketone, caprolactam and lots of unknowns were identified only by SPME method. 1-Phenyl-2-propanone (P2P), 1-phenyl-2-propanol and benzylcyanide peaks could be discriminated clearly by SPME method without interference of amphetamine, an artifact originates from MA degradation. Differences in the impurity patterns resulted in different clustering results. When 48 MA samples were classified into 5 LLE and 5 SPME clusters, cross-matching of the clusters resulted in 8 sub-clusters. It shows that combination of the different extraction methods can distinguish the differences which cannot be distinguished by LLE or SPME method alone, and can improve reliability of the profiling results.
authors.affiliation: National Forensic Service, Seoul 158-707, Republic of Korea.
authors.forename: Jaesin
authors.initials: J
authors.lastname: Lee
authors.forename: Yonghoon
authors.initials: Y
authors.lastname: Park
authors.forename: Wonkyung
authors.initials: W
authors.lastname: Yang
authors.forename: Heesun
authors.initials: H
authors.lastname: Chung
authors.forename: Wonjun
authors.initials: W
authors.lastname: Choi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inoue
authors.forename: Kenji
authors.initials: K
authors.lastname: Kuwayama
authors.forename: Jeonghill
authors.initials: J
authors.lastname: Park